KR101213485B1 - Organometallic complexes and organic electroluminescence device using the same - Google Patents

Abstract

The present invention provides an organic metal complex which emits high efficiency phosphorescence and an organic electroluminescent device using the same. The organometallic complex of the present invention can be used when forming an organic film of an organic electroluminescent device, and emits light in the red wavelength region as a highly efficient phosphorescent material, and has a high luminance and a low driving voltage.

Description

Organometallic Complexes and Organic Electroluminescence Device Using the Same

1A-F schematically show a stacked structure of an organic EL device according to an embodiment of the present invention.

2 illustrates an embodiment of an organic electroluminescent device manufactured according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

10 ... First electrode 11 ... Hole injection layer

12 ... light emitting layer 13 ... hole blocking layer

14 ... second electrode 15 ... electron transport layer

16 ... hole transport layer 20 ... substrate

The present invention relates to an organometallic complex and an organic electroluminescent device using the same, and more particularly, to an organometallic complex capable of emitting light in a red region and an organic electroluminescent device employing it as an organic film forming material.

An organic electroluminescent device (organic EL device) is an active light emitting type using a phenomenon in which light is generated while electrons and holes are combined in an organic film when a current flows through a thin film of fluorescent or phosphorescent organic compound (hereinafter referred to as an organic film). As a display element, it has a light weight, a simple part, a simple manufacturing process, and a wide viewing angle at high image quality. In addition, high color purity and video can be perfectly realized, and low power consumption and low voltage driving make it suitable for portable electronic devices.

A typical organic electroluminescent device has a structure in which an anode is formed on a substrate, and a hole transport layer, a light emitting layer, an electron transport layer, and a cathode are sequentially formed on the anode. Here, the hole transport layer, the light emitting layer and the electron transport layer are organic films made of an organic compound. The driving principle of the organic electroluminescent device having the above-described structure is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode are transferred to the light emitting layer via the hole transport layer. On the other hand, electrons are injected from the cathode to the light emitting layer via the electron transporting layer, and carriers are recombined in the light emitting layer region to generate an exiton. As the excitons are radiated decay, light of a wavelength corresponding to the band gap of the material is emitted.

The light emitting layer forming material of the organic EL device may be classified into a fluorescent material using excitons in a singlet state and a phosphorescent material using a triplet state according to the light emitting mechanism thereof. The fluorescent or phosphorescent material is doped on its own or in a suitable host material to form a light emitting layer, and as a result of electron excitation, singlet excitons and triplet excitons are formed in the host. At this time, the statistical generation ratio of singlet excitons and triplet excitons is 1: 3 (Baldo, et al., Phys. Rev. B, 1999, 60, 14422).

The organic EL device using a fluorescent material as a light emitting layer forming material has the disadvantage that the triplet generated in the host is wasted. Both have the advantage of reaching 100% internal quantum efficiency (Baldo, et al., Nature, Vol. 395, 151-154, 1998). Therefore, when a phosphorescent material is used as a material for forming a light emitting layer, it can have a much higher luminous efficiency than a fluorescent material.

When heavy metals such as Ir, Pt, Rh, and Pd are introduced into organic molecules, triplet and singlet states are induced through spin-orbital coupling caused by heavy atom effects. This results in a forbidden transition, which allows for efficient phosphorescence at room temperature.

As described above, various materials using transition metal compounds, including transition metals such as iridium and platinum, have been disclosed as high-efficiency light emitting materials using phosphorescence. Phosphors are still needed.

The technical problem to be achieved by the present invention is to provide an organometallic complex capable of emitting light efficiently in the red wavelength region.

Another object of the present invention is to provide an organic electroluminescent device employing the organometallic complex.

According to an aspect of the present invention,

It provides an organometallic complex represented by the following formula (1).

Food,

M is Ir, Os, Pt, Pb, Re, Ru or Pd;

The CyN is a substituted or unsubstituted heterocyclic group having 3 to 60 carbon atoms containing nitrogen bonded to M, or a substituted or unsubstituted heteroaryl having 3 to 60 carbon atoms containing nitrogen bonded to M Group;

The CyC is a substituted or unsubstituted carbon ring having 4 to 60 carbon atoms containing carbon bonded to M, a substituted or unsubstituted hetero ring having 3 to 60 carbon atoms containing carbon bonded to M, bonded to M A substituted or unsubstituted aryl group having 3 to 60 carbon atoms containing carbon or a substituted or unsubstituted heteroaryl group having 3 to 60 carbon atoms containing carbon bonded to M;

CyN-CyC represents a cyclometalating ligand bonded to M through nitrogen (N) and carbon (C);

M ₁ is an integer of 0 to 2;

M ₂ is 3-m ₁ ;

A represents a ligand comprising at least two nitrogen atoms and bonded to M via one nitrogen atom;

X is NR ₀ , O, or S, and R ₀ represents hydrogen, a halogen atom, a carboxyl group, or an alkyl group having 1 to 20 carbon atoms;

Q represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.

As the compound of Formula 1, a compound of Formula 2 is preferable.

Food,

M, CyN and CyC are as defined above,

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen, halogen atom, carboxyl group, amino group, nitro group, cyano group, substituted or unsubstituted C _1- C ₂₀ alkyl group, substituted or unsubstituted C ₁ -C ₂₀ alkoxy group, substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, substituted or unsubstituted C ₂ -C ₂₀ alkynyl group, substituted or unsubstituted C ₁ -C ₂₀ heteroalkyl group, substituted or unsubstituted C ₆ -C ₃₀ aryl group, substituted or unsubstituted C ₇ -C ₃₀ arylalkyl group, substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group, or substituted or unsubstituted Ring C ₃ -C ₃₀ heteroarylalkyl group, two or more of them may be fused to each other to form a bicyclic ring to 5 ring fused ring.

Examples of the compound represented by Formula 1 include compounds represented by the following Formulas 3 to 6.

The present invention to achieve the above other technical problem,

An organic electroluminescent device comprising an organic film between a pair of electrodes,

The organic film provides an organic electroluminescent device comprising the above-described organometallic complex.

Hereinafter, the present invention will be described in more detail.

The present invention provides an organometallic complex of formula (1) in which a novel anionic ligand in the form of a triazole derivative is introduced, wherein in the organometallic complex of such a structure, the ligand is an energy gap between the HOMO and triplet MLCT states. The light emission wavelength is shifted to the blue region by several nm by reducing. Therefore, the emission characteristics and the color coordinate control in the red region of the ligand have utility in the organic light emitting device.

≪ Formula 1 >

Food,

M is Ir, Os, Pt, Pb, Re, Ru or Pd;

The CyN is a substituted or unsubstituted heterocyclic group having 3 to 60 carbon atoms containing nitrogen bonded to M, or a substituted or unsubstituted heteroaryl having 3 to 60 carbon atoms containing nitrogen bonded to M Group;

The CyC is a substituted or unsubstituted carbon ring having 4 to 60 carbon atoms containing carbon bonded to M, a substituted or unsubstituted hetero ring having 3 to 60 carbon atoms containing carbon bonded to M, bonded to M A substituted or unsubstituted aryl group having 3 to 60 carbon atoms containing carbon or a substituted or unsubstituted heteroaryl group having 3 to 60 carbon atoms containing carbon bonded to M;

CyN-CyC represents a cyclometalating ligand bonded to M through nitrogen (N) and carbon (C);

M ₁ is an integer of 0 to 2;

M ₂ is 3-m ₁ ;

A represents a ligand comprising at least two nitrogen atoms and bonded to M via one nitrogen atom;

X is NR ₀ , O, or S, and R ₀ represents hydrogen, a halogen atom, a carboxyl group, or an alkyl group having 1 to 20 carbon atoms;

Q represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.

In the organometallic complex of Formula 1, M is a central metal that binds to a cyclometallated ligand or an auxiliary ligand. For example, Ir, Os, Pt, Pb, Re, Ru, or Pd may be used, and preferably Ir or Pt may be used, but is not limited thereto.

CyN in the above formula (1) represents a heterocyclic group or a heteroaryl group containing a nitrogen atom that directly forms a coordination bond with M, which is a central metal. The heterocyclic group represents a substituted or unsubstituted heterocyclic group having 3 to 60 carbon atoms including hetero atoms such as N, O, S, and / or P as a main element forming a ring, and specific examples include pyrrolidine ), Morpholine (morpholine), thiomorpholine (thiomorpholine), thiazolidine and the like, but is not limited thereto. The heteroaryl group represents a substituted or unsubstituted heteroaryl group having 3 to 60 carbon atoms including a hetero atom such as N, O, S, and / or P as a main element forming a ring, and as a specific example, pyridine, 4- Methoxy pyridine, quinoline, pyrrole, indole, pyrazine, pyrazole, imidazole, pyrimidine, quinazoline, thiazole, oxazole, triazine (triazine), 1,2,4-triazole, and the like, but are not limited thereto.

In CyC of Chemical Formula 1, specific examples of a substituted or unsubstituted carbon ring having 4 to 60 carbon atoms including carbon bonded to M include cyclohexane, cyclopentane, and the like, and include carbon bonded to M. Specific examples of the substituted or unsubstituted heterocyclic group having 3 to 60 carbon atoms include tetrahydrofuran, 1,3-dioxane, 1,3-dithiane, and 1,3-dithiolane ( 1,3-dithiolane), 1,4-dioxa-8-azaspiro [4,5] decane {1,4-dioxa-8-azaspiro [4,5] decane}, 1,4-dioxaspiro [ 4,5] decan-2-one {1,4-dioxaspiro [4,5] decan-2-one} and the like, and substituted or unsubstituted aryl having 4 to 60 carbon atoms containing carbon bonded to M. Specific examples of the group include phenyl, 1,3-benzodioxole, biphenyl, naphthalene, anthracene, azulene, and the like, or a substituted or unsubstituted carbon number including carbon bonded to M. 3 to 60 hete Specific examples of the aryl group include thiophene, furan 2 (5H) -furanone, pyridine, coumarin, imidazole, 2-phenylpyridine, 2-benzothiazole, 2-benzooxazole, 1-phenylpyrazole, 1-naphthylpyrazole, 5- (4-methoxyphenyl) pyrazole, 2,5-bisphenyl-1,3,4-oxa Diazole, 2,3-benzofuran 2- (4-biphenyl) -6-phenyl benzoxazole, and the like.

In Formula 1, each substituent of CyN-CyC is connected to each other to form a substituted or unsubstituted 4-7 membered ring group or a substituted or unsubstituted 4-7 membered heterocyclic group, and in particular, a condensed 4-7 membered ring Or a heterocyclic group. Wherein the ring group or heterocyclic group represents a C1-C30 cycloalkyl group, a C1-C30 heterocycloalkyl group, a C6-C30 aryl group or a C4-C30 heteroallyl group, each ring group or heterocyclic group being substituted by one or more substituents Can be. The term "hetero" as used herein refers to a case where a hetero atom such as N, O, P, S or the like is included.

The substituent is a halogen atom, -OR ₁ , -N (R ₁ ) ₂ , -P (R ₁ ) ₂ , -POR ₁ , -PO ₂ R ₁ , -PO ₃ R ₁ , -SR ₁ , -Si (R ₁ ) ₃ , -B (R ₁ ) ₂ , -B (OR ₁ ) ₂ , -C (O) R ₁ , -C (O) OR ₁ , -C (O) N (R ₁ ), -CN, -NO ₂ , -SO ₂ , -SOR ₁ , -SO ₂ R ₁ , -SO ₃ R ₁ , wherein R ₁ is hydrogen, a halogen atom, a substituted or unsubstituted C ₁ -C ₂₀ alkyl group, a substituted or unsubstituted A C ₁ -C ₁₀ alkoxy group, a substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, a substituted or unsubstituted C ₂ -C ₂₀ alkynyl group, a substituted or unsubstituted C ₁ -C ₂₀ heteroalkyl group, a substituted or Unsubstituted C ₆ -C ₄₀ aryl group, substituted or unsubstituted C ₇ -C ₄₀ arylalkyl group, substituted or unsubstituted C ₇ -C ₄₀ alkylaryl group, substituted or unsubstituted C ₂ -C ₄₀ heteroaryl Group and a substituted or unsubstituted C ₃ -C ₄₀ heteroarylalkyl group.

X is NR ₀ , O, or S, and R ₀ represents hydrogen, a halogen atom, a carboxyl group, or an alkyl group having 1 to 20 carbon atoms.

Q represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.

M ₁ is an integer of 0 to 2, m ₂ is 3-m ₁ , preferably m ₁ is 1 or 2, m ₂ is 1 or 2. More preferably m ₁ is 2 and m ₂ is 1.

A represents a ligand comprising two or more nitrogen atoms and bonded with M through one nitrogen, and non-limiting examples of A include substituted or unsubstituted indazole, imidazole, imidazoline, imida. From one selected from zolyl, imidazole derivatives, pyrazole, benzotriazole, benzothiazole, oxadiazole, thiadiazole, pyrazoline, pyrazolidine, benzimidazole, and triazole There is a derivative.

Preferably, A is one selected from the group consisting of triazole, imidazole, pyrazole, and derivatives thereof, more preferably triazole.

The cyclometalated ligand (CyN-CyC) may be represented by the following Chemical Formulas 11 to 37, but is not limited thereto.

Food,

R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are mono- or polysubstituted functional groups irrespective of each other, and are hydrogen, a halogen atom, -OR, -N (R) ₂ , -P (R) ₂ , -POR, -PO ₂ R, -PO ₃ R, -SR, -Si (R) ₃ , -B (R) ₂ , -B (OR) ₂ , -C (O) R, -C (O) OR , -C (O) N (R), -CN, -NO ₂ , -SO ₂ , -SOR, -SO ₂ R, -SO ₃ R, C ₁ -C ₂₀ alkyl group, or C ₆ -C ₂₀ aryl group ego,

R is hydrogen, a halogen atom, a substituted or unsubstituted C ₁ -C ₂₀ alkyl group, a substituted or unsubstituted C ₁ -C ₁₀ alkoxy group, a substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, a substituted or unsubstituted A C ₂ -C ₂₀ alkynyl group, a substituted or unsubstituted C ₁ -C ₂₀ heteroalkyl group, a substituted or unsubstituted C ₆ -C ₄₀ aryl group, a substituted or unsubstituted C ₇ -C ₄₀ arylalkyl group, a substituted or Is selected from an unsubstituted C ₇ -C ₄₀ alkylaryl group, a substituted or unsubstituted C ₂ -C ₄₀ heteroaryl group, and a substituted or unsubstituted C ₃ -C ₄₀ heteroarylalkyl group,

Z is S, O or NR ₀ (R ₀ is hydrogen or a C1-C20 alkyl group).

The organometallic complex of Formula 1 is particularly preferably a compound of Formula 2 below.

<Formula 2>

Food,

M, CyN and CyC are as defined above,

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen, a halogen atom, a carboxyl group, an amino group, a nitro group, a cyano group, a substituted or unsubstituted C ₁ -C ₂₀ alkyl group, substituted or unsubstituted C ₁ -C ₂₀ alkoxy group, substituted or unsubstituted C ₂ -C ₂₀ alkenyl group, substituted or unsubstituted C ₂ -C ₂₀ alkynyl group, substituted or unsubstituted C _1- C ₂₀ heteroalkyl group, substituted or unsubstituted C ₆ -C ₃₀ aryl group, substituted or unsubstituted C ₇ -C ₃₀ arylalkyl group, substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group, or substituted or unsubstituted Ring C ₃ -C ₃₀ heteroarylalkyl group, two or more of them may be fused to each other to form a bicyclic ring to 5 ring fused ring.

Such an organometallic complex of Formula 2 may be more specifically specified as an organometallic complex of Formulas 3 to 5, but is not limited thereto.

<Formula 3>

&Lt; Formula 4 >

&Lt; Formula 5 >

(6)

The organometallic complex represented by Formula 1 according to the present invention is reported by Watts group using [Ir (C ^ N) ₂ Cl] ₂ derivative which is a starting material providing a cyclometallated moiety. Synthesized using the method (FOGarces, RJ Watts, Inorg. Chem. 1988, (35), 2450).

The organic electroluminescent device of the present invention is produced by forming an organic film, in particular a light emitting layer, using the organometallic complex represented by the formula (1). In this case, the organometallic complex represented by Chemical Formula 1 is very useful as a phosphorescent dopant material, which is a light emitting layer forming material, and exhibits excellent light emission characteristics in the red wavelength region.

When the organometallic complex represented by Formula 1 is used as a phosphorescent dopant, the organic layer further includes at least one selected from the group consisting of at least one polymer host, a mixture host of polymers and low molecules, a low molecular host, and a non-luminescent polymer matrix. can do. Here, the polymer host, the low molecular host, and the non-luminescent polymer matrix may be used as long as they are commonly used in forming an emission layer for an organic EL device. Examples of the polymer host include PVK (poly (vinylcarbazole)) and Polyfluorene. , Examples of low molecular weight hosts include CBP (4,4'-N, N'-dicarbazole-biphenyl), 4,4'-bis [9- (3,6-biphenylcarbazolyl)]-1-1,1 ' -Biphenyl {4,4'-bis [9- (3,6-biphenylcarbazolyl)]-1-1,1'-biphenyl}, 9,10-bis [(2 ', 7'-t -Butyl) -9 ', 9' '-spirobifluorenyl anthracene, tetrafluorene (tertfluorene) and the like, and the non-luminescent polymer matrix is polymethyl methacrylate, polystyrene, etc., but is not limited thereto It is not.

The content of the organometallic complex represented by Chemical Formula 1 is preferably 1 to 30 parts by weight based on 100 parts by weight of the total weight of the light emitting layer forming material. If it is less than 1 part by weight, the light emitting material is insufficient and the efficiency and life is lowered, which is not preferable. If it exceeds 30 parts by weight, the triplet quenching phenomenon occurs and the efficiency is lowered, which is not preferable. In order to introduce such an organometallic complex into the light emitting layer, a vacuum deposition method, a sputtering method, a printing method, a coating method, an inkjet method, or the like may be used.

In addition, the organometallic complex represented by Chemical Formula 1 may be used together with a green light emitting material or a blue light emitting material to emit white light.

1A-1F are schematic diagrams illustrating a laminated structure of an organic EL device according to exemplary embodiments of the present invention.

Referring to FIG. 1A, a light emitting layer 12 including the biphenyl derivative of Chemical Formula 1 is stacked on the first electrode 10, and a second electrode 14 is formed on the light emitting layer 12.

Referring to FIG. 1B, an emission layer 12 including the biphenyl derivative of Chemical Formula 1 is stacked on the first electrode 10, and a hole suppression layer (HBL) 13 is stacked on the emission layer 12. The second electrode 14 is formed thereon.

In the organic EL device of FIG. 1C, a hole injection layer (HIL) 11 is formed between the first electrode 10 and the light emitting layer 12.

The organic EL device of FIG. 1D has the same stacked structure as that of FIG. 6C except that an electron transport layer (ETL) 15 is formed instead of the hole suppression layer (HBL) 13 formed on the light emitting layer 12. .

In the organic EL device of FIG. 1E, instead of the hole suppression layer (HBL) 13 formed on the light emitting layer 12 containing the biphenyl derivative of Formula 1, the hole suppression layer (HBL) 13 and the electron transport layer 15 are formed. Except for using a two-layer film sequentially stacked, it has the same laminated structure as in the case of Fig. 6C. In some cases, an electron injection layer may be further formed between the electron transport layer 15 and the second electrode 14 in the organic EL device of FIG. 6E.

The organic EL device of FIG. 1F has the same structure as the organic EL device of FIG. 6E except that a hole transport layer 16 is further formed between the hole injection layer 11 and the light emitting layer 12. In this case, the hole transport layer 16 plays a role of suppressing impurity penetration from the hole injection layer 11 into the light emitting layer 12.

The organic EL device having the laminated structure described above can be formed by a conventional manufacturing method, and the manufacturing method is not particularly limited.

Herein, the thickness of the organic film is preferably 30 to 100 nm. If the thickness of the organic film is less than 30 nm, the efficiency and lifespan are lowered. If the thickness is greater than 100 nm, the driving voltage increases, which is not preferable.

Meanwhile, the organic film refers to a film made of an organic compound formed between a pair of electrodes in an organic electroluminescent device, such as an electron transport layer and a hole transport layer, in addition to the light emitting layer.

In the organic electroluminescent device, a buffer layer may be formed between each layer. As a material of the buffer layer, a material commonly used may be used. Preferably, copper phthalocyanine or polythiophene is used. ), Polyaniline (polyaniline), polyacetylene (polyacetylene), polypyrrole (polypyrrole), polyphenylene vinylene (polyphenylene vinylene), or derivatives thereof may be used, but is not limited thereto.

As a material of the hole transporting layer, a commonly used material may be used, and polytriphenylamine may be preferably used, but the present invention is not limited thereto.

As a material of the electron transport layer, a material commonly used may be used. Preferably, polyoxadiazole may be used, but is not limited thereto.

A material commonly used as the material of the hole blocking layer may be used, and preferably, LiF, BaF ₂ or MgF ₂ may be used, but is not limited thereto.

The fabrication of the organic electroluminescent device of the present invention does not require any special device or method, and can be manufactured according to a method of fabricating an organic electroluminescent device using a common light emitting material.

The organometallic complex of Formula 1 according to the present invention may emit light in the region of about 550 to about 650 nm. The light emitting diode using the organometallic complex can be used for light source lighting for full color display, backlight, outdoor billboard, optical communication, interior decoration, and the like.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

Reference Example 1 Synthesis of 1-phenylisoquinoline iridium dimer

<Reaction Scheme 1>

As described in Scheme 1, 5 g (31 mmol) of 1-chloroisoquinoline (1-chloroisoqinoline) of Formula 41 and 25.00 g (1.58 x 10 ⁴ mmol) of phenylboronic acid of Formula 42 ( phenyl boronic acid), 2 mL of sodium carbonate solution made with 100 mL of toluene, 48 mL of ethanol and 95 mL of water were added, which was stirred at room temperature under nitrogen atmosphere. Subsequently, 4.53 g (3.92 mmol) of tetrakis (triphenylphosphine) palladium (0) was added to the reaction mixture, and the mixture was refluxed for 15 hours while blocking light under a nitrogen atmosphere.

When the reaction was completed, the temperature of the reaction mixture was adjusted to room temperature, extracted with ethyl acetate and water, separated by column chromatography (toluene: hexane = 10: 1), and a pale brown liquid (1) -Phenylisoquinoline).

1-phenylisoquinoline iridium dimer of Formula 44 as a yellow powder was synthesized using 1-phenylisoquinoline monomer and IrCl ₃ 3H ₂ O synthesized according to the above procedure. The synthesis method is described in J. Am. Che. Soc., 1984, 106, 6647-6653.

¹ H-NMR (CD ₂ Cl ₂ , ppm): 9.04 (d, 1H0, 8.96 (d, 1H), 8.12 (d, 1H), 7.83 (d, 2H), 7.78 (t, 2H), 6.82 (t , 1H), 6.55 (d, 1H), 6.50 (t, 1H), 6.03 (d, 1H)

Reference Example 2 Synthesis of 2-phenylquinoline Iridium Dimer

<Reaction Scheme 2>

As described in Scheme 2, except that 5g (31mmol) of 2-chloroquinoline of Formula 51 is used instead of 1-chloroisoquinoline, the method of Formula 54 of 2- Phenylquinoline iridium dimer was synthesized.

Reference Example 3: Synthesis of 1-biphenylisoquinoline iridium dimer

<Reaction Scheme 3>

As described in Scheme 3, 6.1 g (31 mmol) of 4,4'-biphenyl boronic acid was used instead of phenylboronic acid, using the same method as in Reference Example 1, except that 1-biphenyl isoquinoline iridium dimer was synthesized.

Reference Example 4: Synthesis of 4'-trimethylsilyl-phenylisoquinoline iridium dimer

<Reaction Scheme 4>

As described in Scheme 3, 6-g (31 mmol) of 4'-silylphenyl boronic acid was used instead of phenylboronic acid, using the same method as in Reference Example 1, except that Biphenylisoquinoline iridium dimer was synthesized.

¹ H NMR (CDCl ₃ , ppm): 9.47 (d, 1H), 8.95 (d, 1H), 8.05 (d, 1H), 7.91 (d, 1H), 7.81-7.72 (m, 2H), 6.95 (t , 1H), 6.05 (s, 1H), -0.26 (9H, trimethylsilyl group)

Example 1 Synthesis of Compound Represented by Formula 3

0.4 ml of [Ir (1-phenylisoquinolie) ₂ Cl] ₂ of formula 44, 3- (2H-benzotriazol-2-yl) -4-hydroxyphenyl methane 0.88 in a 250 ml branched flask under nitrogen atmosphere. After mmol was dissolved in 40 mL of trichloromethane, the reaction was performed at room temperature for 2 to 10 hours. After the reaction was completed, the reaction solution was filtered through Celite and precipitated in hexane to give triazole phenolate. In the reactor, 0.5 mmol of the red product was dissolved in 20 ml of trichloromethane, 2.0 mmol of sodium carbonate was dissolved in 15 ml of methanol, added to the reactor, followed by stirring at room temperature for 0.5 to 24 hours. After completion of the reaction, the reaction solution was filtered through Celite and precipitated in hexane to give the compound of Formula 3 as a red solid. The red solid obtained was purified using a silica gel column (methylene chloride: acetone = 10: 1). The structure of the final object was analyzed via ¹ H NMR spectrum:

¹ H-NMR (CD ₂ Cl ₂ , ppm): 9.07 (t, 2H), 8.90 (d, 1H), 8.41 (d, 1H), 8.11 (d, 1H), 7.93 (d, 1H), 7.85 ( t, 2H), 7.75-7.61 (m, 5H), 7.33 (1H), 7.15 (t, 1H), 7.05 (d, 1H), 6.99 (d, dH), 6.92 (t, 1H), 6.90-6.65 (m, 4H), 6.47 (d, 1H), 6.29 (d, 1H), 6.13 (d, 1H), 6.06 (d, 1H), 2.25 (s, 3H, methyl)

Example 2: Synthesis of Compound Represented by Formula 4

The compound of Chemical Formula 4 was synthesized in the same manner as in Example 1, except that 2-phenylquinoline iridium dimer of Chemical Formula 54 was used instead of 1-phenylisoquinoline iridium dimer.

Example 3. Synthesis of Compound Represented by Chemical Formula 5

A compound of Chemical Formula 5 was synthesized in the same manner as in Example 1, except that 1-biphenylisoquinoline iridium dimer of Chemical Formula 66 was used instead of 1-phenylisoquinoline iridium dimer.

Example 4. Synthesis of Compound Represented by Chemical Formula 6

A compound of Chemical Formula 6 was synthesized in the same manner as in Example 1, except that 1- (4'-trimethylsilyl) phenylisoquinoline iridium dimer of Chemical Formula 74 was used instead of 1-phenylisoquinoline iridium dimer. The structure of the final target was confirmed by analysis via ¹ H NMR spectrum:

¹ H-NMR (CDCl ₃ , ppm): 9.05 (m, 2H), 8.87 (d, 1H), 8.30 (d, 1H), 8.03 (t, 2H), 7.90 (t, 2H), 7.78-7.72 ( m, 3H), 7.67-7.64 (m, 3H), 7.39 (d, 1H), 7.17 (d, 2H), 7.04 (t, 2H), 6.88 (s, 1H), 6.79 (t, 1H), 6.54 (d, 1H), 6.30 (d, 1H), 5.98 (s, 1H), 5.81 (d, 1H), 2.17 (s, 3H methyl group), -0.11 (s, trimethylsilyl group), -0.28 (s , 9H trimethylsilyl group)

Photoluminescence of the compounds of Chemical Formulas 3 to 6 obtained according to the above procedure was dissolved in methylene chloride to form a 10 ^-4 M solution, and then the luminescence properties in the solution state were investigated. The luminescent properties in the film state were investigated by spin coating the compound on the film.

The luminescence properties and CIE (color coordinates) properties of the compounds of Chemical Formulas 3 to 6 obtained from Examples 1 to 4 are shown in Table 1 below:

division PL characteristics
? _max (nm) CIE color coordinates
(x, y) solution film solution film

Example 1:

617 631 (0.65, 0.34) (0.67, 0.32) Example 2:

595 - (0.58, 0.41) - Example 3

632 - (0.68, 0.31) - Example 4

634 - (0.68, 0.31) -

From the above Table 1, a triazole derivative is introduced as an auxiliary ligand to form a dopant having excellent phosphorescence properties, and in particular, it is suitable as a phosphorescent material that emits light in a red region by a strong electronic effect due to introduction of a substituent. Able to know.

Fabrication of Organic Electroluminescent Device

Example 5

After the transparent electrode substrate coated with indium-tin oxide (ITO) was thoroughly cleaned, an ITO electrode pattern was formed by patterning ITO with a photoresist resin and an etchant, and then cleaned again . PEDOT {poly (3,4-ethylenedioxythiophene)} [AI 4083] -PSS was coated on the resultant in a thickness of about 50 nm, and then baked at 120 ° C. for about 5 minutes to form a hole injection layer. Formed.

A solution of PVK, CBP (PVK: CBP = 4: 5) and 8% by weight of the dopant of Formula 3 in chloroform was spin-coated on the hole injection layer to form a light emitting layer having a thickness of 85 nm. Subsequently, Balq is vacuum-deposited to form a 20 nm thickness while maintaining a vacuum degree of 4 × 10 ⁻⁶ torr or less using a vacuum evaporator on the upper portion of the polymer light emitting layer, and an electron transport layer having a thickness of 15 nm is formed by vacuum evaporation of Alq. LiF was vacuum deposited at a rate of 0.1 / sec to form an electron injection layer having a thickness of 1 nm.

Subsequently, Al was deposited at a rate of 10 mA / sec to deposit and encapsulate an anode having a thickness of 150 nm, thereby completing an organic EL device. At this time, the encapsulation process was carried out by putting BaO powder in a glove box under a dry nitrogen gas atmosphere, sealing it with a metal can, and finally treating it with a UV curing agent. The structure of the device is ITO / PEDOT-PSS (50 nm) / PVK-CBP (4: 5) -dopant 8% by weight (85 nm) / Balq (20 nm) / Alq (15 nm) / LiF (1 nm) / Al (150 nm). The EL device was a multilayered device, and its schematic structure was as shown in Fig. 2, and the light emitting area was 6 mm &lt; ^{2 &} gt ;.

Example 6

An EL device was manufactured in the same manner as in Example 5, except that the compound of Formula 4 was used instead of the compound of Formula 5.

Example 7

An EL device was manufactured in the same manner as in Example 5, except that the compound of Formula 5 was used instead of the compound of Formula 5.

Example 8

An EL device was manufactured in the same manner as in Example 5, except that the compound of Formula 6 was used instead of the compound of Formula 5.

Comparative example

An EL device was manufactured in the same manner as in Example 5, except that the compound of Formula 7 was used instead of the compound of Formula 3.

<Formula 7>

The electroluminescent properties, CIE (color coordinates), current efficiency, driving voltage, and luminance characteristics of Example 5 and Comparative Examples are shown in Table 2 below.

division EL
? _max (nm) CIE
(x, y) Current density
(mA / cm ² ) Driving voltage
(V) Brightness
(cd / m &lt; 2 & Example 5 620 (0.66, 0.32) 16.3 mA / cm ² at 10 V 5.5 4541 at 13.5 V Comparative example 628 (0.68, 0.31) 1.69 mA / cm ² at 13 V 7.5 2690 at 21.5 V

The electroluminescent device of Example 5 employing the compound of Formula 3 according to the present invention from Table 2 has high luminance in the red light emitting region, can be driven at low voltage, and has a high current density even at low voltage. It can be seen.

The organometallic complex according to the present invention can efficiently emit light in the red region, and the organometallic complex can be used to form an organic film of the organic electroluminescent device, and is a high-efficiency phosphorescent material in the 550-650 nm wavelength region. In addition to emitting light, white light may be used in combination with a green light emitting material or a blue light emitting material.

Claims (12)

An organometallic complex characterized in that the compound of formula 3 to 6. <Formula 3>

&Lt; Formula 4 >

&Lt; Formula 5 >

(6)

delete delete delete delete delete delete An organic electroluminescent device comprising an organic film between a pair of electrodes, The organic electroluminescent device according to claim 1, wherein the organic film contains the organometallic complex of claim 1. The organic electroluminescent device according to claim 8, wherein the organic film is a light emitting layer. The organic electroluminescent device according to claim 8, wherein the content of the organometallic complex is 1 to 30 parts by weight based on 100 parts by weight of the total weight of the light emitting layer forming material. The organic electroluminescent device according to claim 8, wherein the organic film further comprises at least one selected from the group consisting of at least one polymer host, a mixture of a polymer host and a low molecular host, a low molecular host, and a non-luminescent polymer matrix. . The organic electroluminescent device according to claim 8, wherein the organic layer further comprises a green light emitting material or a blue light emitting material.

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